1. Field of the Invention
The invention relates generally to the field of medical and surgical instruments, and more particularly to surgical instruments for manipulating and clamping the kidneys.
2. Description of Related Art
A nephrectomy is a surgical procedure in which a kidney is removed. Nephrectomies may be performed, for example, in cases of renal cell carcinoma, kidney deformity, trauma, and for live donor transplants. In a typical nephrectomy, the connections of the kidney to the renal artery and vein and to the ureter are severed and the kidney is removed. In 2008, 55,000 nephrectomies were performed, of which 50% were performed laparoscopically, i.e., through several small incisions in the abdomen, rather than by directly exposing the kidney with a large incision.
However, a full or “radical” nephrectomy is not indicated in every case. A partial nephrectomy, removal of only a portion of a kidney, may be indicated, for example, in cases in which there is a tumor in one kidney and the other kidney is functioning poorly, or in cases in which there are tumors in both kidneys. In general, partial nephrectomies may result in less morbidity, less blood loss, shorter recovery time, reduced need for pain medication, and conserved kidney function.
In a partial nephrectomy, although only a portion of the kidney is removed, the renal artery is typically clamped, cutting off blood flow to the entire kidney, not just the portion requiring removal. Once the renal artery has been clamped, the surgeon has 30 minutes to excise the tumor, restore hemostasis, and repair both the urine collection system and the defect created by the procedure. After 30 minutes, ischemia from lack of blood flow can cause tissue damage. Thus, the procedure is difficult and has a steep learning curve. Tools and procedures that allow for clamping off only an affected portion of the renal blood supply would make the partial nephrectomy easier and perhaps make the procedure more widely used.
Unfortunately, surgical tools that allow for clamping off only a portion of the renal blood supply are relatively few. As one example, U.S. Patent Application Publication No. 2004/0158286 discloses a hemostatic tissue clamp. However, most embodiments of that clamp are designed to be used only with an open surgical procedure, in which the entire kidney is exposed. Those embodiments that are designed for laparoscopic use have an extremely complex jaw mechanism.